ABSTRACT We present results of a stellar occultation by the Jupiter Trojan asteroid Patroclus and its nearly equal size moon, Menoetius. The geocentric mid-time of the event was 2013 October 21 ...06:43:02 UT. Eleven sites out of 36 successfully recorded an occultation. Seven chords across Patroclus yielded an elliptical limb fit of 124.6 by 98.2 km. There were six chords across Menoetius that yielded an elliptical limb fit of 117.2 by 93.0 km. There were three sites that got chords on both objects. At the time of the occultation we measured a separation of 664.6 km (0.247 arcsec) and a position angle for Menoetius of 265 7 measured eastward from J2000 north. Combining this occultation data with previous light curve data, the axial ratios of both objects are 1.3 : 1.21 : 1, indicative of a mostly oblate ellipsoid with a slight asymmetry in its equatorial projection. The oblate shape is not an equilibrium shape for the current rotation period, but would be if it were rotating with an ∼8 h period. This faster period is consistent with a pre-evolved state of the system with an orbital separation that is 50% smaller. Our best estimate of the system density is 0.88 g cm−3.
Evaluating health risks of environmental contaminants can be better achieved by considering toxic impacts across species. Hexavalent chromium Cr(VI) is a marine pollutant and global environmental ...contaminant. While Cr(VI) has been identified as a human lung carcinogen, health effects in marine species are poorly understood. Little is known about how Cr(VI) might impact humans and marine species differently. This study used a One Environmental Health Approach to compare the cytotoxicity and genotoxicity of particulate Cr(VI) in human and leatherback sea turtle (Dermochelys coriacea) lung fibroblasts. Leatherbacks may experience prolonged exposures to environmental contaminants and provide insight to how environmental exposures affect health across species. Since humans and leatherbacks may experience prolonged exposure to Cr(VI), and prolonged Cr(VI) exposure leads to carcinogenesis in humans, in this study we considered both acute and prolonged exposures. We found particulate Cr(VI) induced cytotoxicity in leatherback cells comparable to human cell data supporting current research that shows Cr(VI) impacts health across species. To better understand mechanisms of Cr(VI) toxicity we assessed the genotoxic effects of particulate Cr(VI) in human and leatherback cells. Particulate Cr(VI) induced similar genotoxicity in both cell lines, however, human cells arrested at lower concentrations than leatherback cells. We also measured intracellular Cr ion concentrations and found after prolonged exposure human cells accumulated more Cr than leatherback cells. These data indicate Cr(VI) is a health concern for humans and leatherbacks. The data also suggest humans and leatherbacks respond to chemical exposure differently, possibly leading to the discovery of species-specific protective mechanisms.
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•Cr(VI) is cytotoxic and genotoxic to leatherback sea turtle lung cells.•Leatherback and human cells respond differently to Cr(VI).•Cr(VI) exposure is a health concern for humans and leatherback sea turtles.
ABSTRACT
We infer the intrinsic ionized gas kinematics for 383 star-forming galaxies across a range of integrated star formation rates (SFR ∈ 10−3, 102 M⊙ yr−1) at z ≲ 0.1 using a consistent 3D ...forward-modelling technique. The total sample is a combination of galaxies from the Sydney-AAO Multiobject Integral field Spectrograph (SAMI) Galaxy survey and DYnamics of Newly Assembled Massive Objects survey. For typical low-z galaxies taken from the SAMI Galaxy Survey, we find the vertical velocity dispersion (σv,z) to be positively correlated with measures of SFR, stellar mass, H i gas mass, and rotational velocity. The greatest correlation is with SFR surface density (ΣSFR). Using the total sample, we find σv,z increases slowly as a function of integrated SFR in the range SFR ∈ 10−3, 1 M⊙ yr−1 from 17 ± 3 to 24 ± 5 km s−1 followed by a steeper increase up to σv,z ∼80 km s−1 for SFR ≳ 1 M⊙ yr−1. This is consistent with recent theoretical models that suggest a σv,z floor driven by star formation feedback processes with an upturn in σv,z at higher SFR driven by gravitational transport of gas through the disc.
To achieve optimal health and oral health, the system of care must place a person and their social well-being at the center of decision making and understand factors spent outside the clinical ...settings, including individual behavior, context and lifestyle.
Person-centered care offers a unique and compelling opportunity for dentistry, and its practitioners, to improve quality of care and overall health outcomes. For decades, the dominant treatment modalities within dentistry primarily focused on a surgical, treatment-oriented approach as opposed to health promotion and improvement. However, new business and care models are disrupting the dental care system, and transforming it into one that is focused on disease management and prevention-oriented primary care that considers overall health and well-being. We proposed a person-centered care model to improve oral health as an integral part of overall health. The model identified three key players who act as change agents with their respective roles and responsibilities: Person, provider, and health care system designer.
While previous person-centered models in dentistry focused on the role of providers within the clinical setting, this work emphasizes the role of the care designer in creating an environment where both person and provider are able to communicate effectively and achieve improved health outcomes.
By age 6, children typically share an equal number of resources between themselves and others. However, fairness involves not merely that each person receive an equal number of resources ("numerical ...equality") but also that each person receive equal quality resources ("quality equality"). In Study 1, children (N = 87, 3–10 years) typically split four resources "two each" by age 6, but typically monopolized the better two resources until age 10. In Study 2, a new group of 6- to 8-year-olds (N = 32) allocated resources to third parties according to quality equality, indicating that children in this age group understand that fairness requires both types of equality.
Abstract
We present a large high-resolution study of the distribution and evolution of C
iv
absorbers, including the weakest population with equivalent widths
. By searching 369 high-resolution, high ...signal-to-noise ratio spectra of quasars at
from Keck/HIRES and VLT/UVES, we find 1268 C
iv
absorbers with
Å (our ∼50% completeness limit) at redshifts
. A Schechter function describes the observed equivalent width distribution with a transition from power-law to exponential decline at
. The power-law slope
α
rises by ∼7%, and the transition equivalent width
W
⋆
falls by ∼20% from
to 3.6. We find that the comoving redshift path density,
, of
Å absorbers rises by ∼1.8 times from
z
≃ 4.0 to 1.3, while the
Å
rises by a factor of ∼8.5. We quantify the observed evolution by a model in which
decreases linearly with increasing redshift. The model suggests that populations with larger
thresholds evolve faster with redshift and appear later in the universe. The cosmological
Technicolor Dawn
simulations at
z
= 3–5 overproduce the observed abundance of absorbers with
while yielding better agreement at higher
. Our empirical linear model successfully describes C
iv
evolution in the simulations and the observed evolution of
Å C
iv
for the past
. Combining our measurements with the literature gives us a picture of C
iv
absorbing structures becoming more numerous and/or larger in physical size over the last
of cosmic time (
z
∼ 6–0).
The tensile mechanical properties of metals manufactured by laser powder bed fusion (L-PBF) are known to vary systematically between builds, posing challenges for the qualification and adoption of ...L-PBF. In this work, we systematically investigated two mechanisms that have previously been used to explain systematic differences in mechanical behavior of notionally identical L-PBF samples between builds (so called “inter-build variation”): porosity and laser parameter drift. Over 250 tension coupons, each with unique laser processing parameters, were built in 316 L stainless steel across three L-PBF builds, screened using high-resolution X-ray Computed Tomography to quantify internal porosity, and then mechanically tested. Notionally identical samples from one build showed statistically significant differences in porosity (0.045%, vs. 0.001% for the “best” build), ultimate tensile strength (614 vs. 588 MPa), and elongation (0.267 vs. 0.321 strain to failure), revealing meaningful levels of inter-build variation. Statistical and machine-learning guided interrogation of the relationships between laser processing conditions, porosity and mechanical response showed that the both laser parameter drift and systematic differences in porosity can both adequately explain observations of inter-build variation, but their effects are nonlinear and are most relevant in different regimes of build quality. In the present case, laser parameter drift within high-density samples can result in material with improved strength and reduced ductility due to microstructural refinement; on the other hand, porosity above ∼0.1% that is caused by process drift or other means contributes to rapid embrittlement, as in (Boyce et al., 2017).
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